This experiment seeks to delineate the morphogenesis of pancreatic adenocarcinoma induced by 2,2'-dihydroxy-di-N-propylnitrosamine (DIPN) through use of 1) high resolution light microscopy, 2) transmission electron microscopy, and 3) qualitative microscopic autoradiography. Consisting of 4 experiments, the design will employ a serial sacrifice of 60 random-inbred male Syrian Golden hamsters receiving 250 mg/kg body weight of DIPN once weekly in olive oil subcutaneously, with an equal control group, beginning at 8 weeks of age, at 1, 2, 5, 10, 12, 17, 20,22, 25, 30 and 41 weeks. The animals will have received 3H- thymidine IP one hour prior to sacrifice. Sections of pancreas will be examined by high resolution light microscopy, transmission electronmicroscopy and light microscope autoradiography. A second experiment will seek to reproduce the findings of Pour et al. (Am. J. Pathol. 76: 349-358, 1974). A third will examine uptake and localization of H3-DIPN; and a fourth will examine the effect of substituting a hydroxylic, hydrophilic solvent such as glycerol for the olive oil vehicle.